It is proposed that an interdepartmental Confocal Fluorescent Microscopy facility will be established by purchase of a Ziess Axiophot research microscope and an MRC Lasersharp Confocal Imaging System. The facility will be used both for conventional fluorescent microscopy and confocal imaging of thick specimens, taking advantage of the unique capability of confocal optics to provide high resolution images through rejection of out- of-focus glare. In particular, the facility will be used to 1) study the localization of cell surface and cytoskeletal proteins in normal polarized epithelial cells and oncogenically transformed variants, 2) investigate the distribution of junctional proteins in cultured cells, tissues, and microinjected Xenopus oocytes, 3) analyze pattern formation in early leech embryos, 4) determine changes in cytoskeletal organization during fertilization in the sea urchin, 5) study the innervation of the laryngeal mucosa, 6) find factors involved in establishment of positional information in the embryonic eye, and 7) investigate cell wound healing in vivo in injured and normal gut.